WO2019188304A1

WO2019188304A1 - Detection device

Info

Publication number: WO2019188304A1
Application number: PCT/JP2019/010348
Authority: WO
Inventors: 智和酒井; 陽平松葉
Original assignee: パイオニア株式会社
Priority date: 2018-03-29
Filing date: 2019-03-13
Publication date: 2019-10-03
Also published as: JP6992164B2; JPWO2019188304A1

Abstract

Provided is a detection device that can improve the detection accuracy of a specific substance through improvement of use efficiency of excitation light and fluorescent light and that can achieve device miniaturization. This detection device has: a reaction part that is disposed on one axis and that includes a solution flow path through which a solution containing a coenzyme excited by excitation light to emit fluorescent light flows, a gas flow path through which a gas sample flows, and an oxygen holding film that holds oxygen for catalyzing reaction of the gas sample together with the coenzyme; a waveguide member that is provided in contact with the reaction part on the axis and that forms a waveguide along the axis; and a detection part that is disposed on the axis and that detects the fluorescent light that has passed through the waveguide.

Description

Detection device

The present invention relates to a detection apparatus for detecting a substance contained in a gas sample.

A detection device that detects a specific substance contained in a gas sample by detecting a decrease in coenzyme accompanying an enzyme reaction is known.

As such a detection device, for example, the detection of a substrate contained in a gas sample can be performed by using a decrease in NADH which is a coenzyme with the reaction of a ketone such as acetone or a substrate such as nonenal. A biosensor system to be performed is disclosed in Patent Document 1. Specifically, the biosensor system of Patent Document 1 detects a decrease in coenzyme by using fluorescence when the specific enzyme is irradiated with specific excitation light.

JP 2016-220573 A

Here, the amount of fluorescence emitted by the coenzyme affects the detection accuracy. Therefore, in order to increase the amount of detectable fluorescence, it is conceivable to efficiently irradiate the coenzyme with excitation light emitted from the light source and efficiently guide only the fluorescence emitted by the coenzyme to the detection unit. For this reason, in the biosensor system of Patent Document 1, an optical fiber probe is arranged in the vicinity of an enzyme in which the concentration of the coenzyme changes due to the substrate, through which the coenzyme is irradiated with excitation light, and the coenzyme The fluorescence emitted from is detected.

However, the numerical aperture (NA) of the optical fiber is small, so when combined with a light source necessary for the construction of the device and a lens having an appropriate numerical aperture, the utilization efficiency of the excitation light is remarkably reduced, and fluorescence is detected. One of the issues is that efficiency is similarly low.

Also, when the detection device is mounted on a moving body such as an automobile, the mounting space is limited. For this reason, the detection device is required to be reduced in size by reducing the number of parts.

The present invention has been made in view of the above points, and is a detection device capable of improving the detection accuracy of a specific substance by improving the utilization efficiency of excitation light and fluorescence and reducing the size of the device. Is one of the issues.

The detection device according to claim 1 of the present invention is a solution that holds a solution containing a coenzyme that emits fluorescence by being excited by excitation light before or after a catalytic reaction with the gas sample, through which a gas sample flows. A holding part, and a reaction part including an enzyme holding film holding an enzyme serving as a catalyst for the catalytic reaction and arranged on one axis, and provided on the one axis in contact with the reaction part And a light guide member that forms a light guide path along the one axis, and a detection unit that detects the fluorescence that has passed through the light guide path.

1 is a cross-sectional view illustrating a configuration of a detection device according to Example 1. FIG. It is an expanded sectional view of the reaction part of FIG. FIG. 6 is an explanatory diagram illustrating an optical path of excitation light of the detection apparatus according to the first embodiment. FIG. 3 is an explanatory diagram for explaining an optical path of fluorescence of the detection apparatus according to the first embodiment. 6 is a cross-sectional view illustrating a configuration of a detection device according to Example 2. FIG. FIG. 6 is an explanatory diagram illustrating an optical path of excitation light of a detection device according to Example 2. FIG. 10 is a cross-sectional view illustrating a configuration of a detection device according to a modification example of Example 2. 6 is a cross-sectional view illustrating a configuration of a detection device according to Embodiment 3. FIG. FIG. 6 is a cross-sectional view illustrating a configuration of a detection device according to Example 4. FIG. 10 is an explanatory diagram illustrating an optical path of excitation light of a detection device according to Example 4. FIG. 10 is an explanatory diagram for explaining an optical path of fluorescence of a detection apparatus according to Example 4. 10 is a cross-sectional view illustrating a configuration of a detection device according to Embodiment 5. FIG. FIG. 10 is a cross-sectional view illustrating a configuration of a detection device according to Example 6.

FIG. 1 shows a cross section along one axis AX of a biosensor 10 as a detection apparatus according to an embodiment of the present invention.

In FIG. 1, a biosensor 10 as a detection device is a device that detects fluorescence emitted by a coenzyme that binds to an apoenzyme and detects a substrate that is a detection target.

Specifically, the coenzyme used for detection of the substrate of the biosensor 10 is excited by excitation light in one state before and after the reaction of the substrate and emits fluorescence. Therefore, the biosensor 10 detects the substrate by utilizing the change in the amount of fluorescence emitted by the coenzyme due to the reaction of the substrate.

For example, as shown in Chemical Formula 1, when NADH (reduced nicotinamide adenine dinucleotide) is used as a coenzyme, the enzyme S-ADH catalyzes the reaction in which the substrate acetone is reduced to 2-propanol. To do. At this time, NADH which is a coenzyme is oxidized to NAD + (oxidized nicotinamide adenine dinucleotide) by an enzymatic reaction.

Here, NADH emits fluorescence upon receiving excitation light of a predetermined wavelength, but does not emit fluorescence even when NAD + receives excitation light of the same wavelength. Therefore, the fluorescence intensity detected before and after this reaction varies.

The biosensor 10 of the present invention is a device that measures the concentration of a substrate by measuring the amount of fluorescence emitted from the NADH.

In FIG. 1, a light source LT is a light emitting device that emits excitation light. The light source LT is, for example, an ultraviolet light emitting diode that emits ultraviolet light having a peak wavelength of 340 nm as excitation light. The light emitting device is not limited to the ultraviolet light emitting diode, and for example, an ultraviolet laser diode, a mercury lamp, or the like can be used.

On one axis AX, an excitation light optical system 20 that is an optical system for the excitation light emitted from the light source LT is provided. The excitation light optical system 20 condenses the excitation light toward one axis AX. One axis AX is the same axis as the optical axis of the excitation light in this embodiment.

The excitation light optical system 20 includes a collimator lens 21 that converts the excitation light into parallel light, and a ball lens 22 that is a condenser lens that condenses the excitation light that has been converted into parallel light by the collimator lens 21 onto one axis AX. including. The excitation light optical system 20 is configured to have at least a numerical aperture higher than that of the optical fiber.

In addition, since the focal length of the ball lens 22 is short among the condenser lenses, the configuration of the biosensor 10 can be further reduced. Further, the ball lens 22 has a large numerical aperture (NA) among the condensing lenses, and can take in more excitation light.

Between the ball lens 22 and the collimating lens 21, an excitation light bandpass filter EF that transmits the wavelength of the excitation light is provided. The band transmitted by the excitation light bandpass filter EF is a band including the wavelength of excitation light excited by the coenzyme. In this example, NADH is used as a coenzyme. NADH absorbs ultraviolet rays of 340 nm and emits fluorescence. Accordingly, the range of wavelengths transmitted by the excitation light bandpass filter EF is 330 to 350 nm.

A flow cell 30 is provided on one on-axis AX. The flow cell 30 functions as a reaction unit in which the enzyme reaction shown in Chemical Formula 1 is performed. The flow cell 30 includes a gas channel 31 through which a gas sample containing a substrate flows, a solution channel 32 as a solution holding unit that holds a solution containing a coenzyme, and an enzyme holding film 33 that holds an enzyme. Here, the solution flow path 32 may have a structure such as a tube through which a solution containing a coenzyme flows, or may have a structure such as a sealed container that does not flow a solution. Good.

The substrate contains either a ketone group or an aldehyde group. A coenzyme that emits fluorescence when excited by excitation light in one state before and after the reaction of the substrate is used. Examples of such coenzymes include NADH and NADPH (reduced nicotinamide adenine dinucleotide phosphate). The coenzyme reversibly changes its chemical structure between two states before and after the reaction of the substrate.

When NADH or NADPH is used as a coenzyme, for example, alanine dehydrogenase, alcohol dehydrogenase, aldehyde dehydrogenase, isocitrate dehydrogenase, uridine-5′-diphospho-glucose dehydrogenase, galactose dehydrase Elementary enzyme, formate dehydrogenase, glyceraldehyde-3-phosphate dehydrogenase, glycerol dehydrogenase, glycerol-3-phosphate dehydrogenase, glucose dehydrogenase, glucose-6-phosphate dehydrogenase, Glutamate dehydrogenase, cholesterol dehydrogenase, sarcosine dehydrogenase, sorbitol dehydrogenase, carbonic acid dehydrogenase, lactate dehydrogenase, 3-hydroxybutyrate dehydrogenase, pyruvate dehydrogenase, fructose dehydrogenase, 6 -Phosphogluconate dehydrogenase, formaldehyde dehydrogenase Examples thereof include mannitol dehydrogenase, malate dehydrogenase, leucine dehydrogenase and the like, and in particular, NADH or NADPH is used as an electron donor, and ketone (acetone, 2-butanone, 2-pentanone, etc.) or aldehyde ( Nonalal, ethyl vinyl ketone, etc., more specifically, secondary alcohol dehydrogenase (S-ADH) (secondary alcohol dehydrogenase (EC: 1.1.1.x)), Enone reductase (ER1) (enone reductase type 1, ER1) and the like can be used.

The light guide member 40 is provided in contact with the flow cell 30 on one axis AX. The light guide member 40 is formed in a cylindrical shape in the present embodiment. The light guide member 40 may have a shape other than a cylindrical shape, and may be, for example, a cylindrical shape having a non-planar end surface, a polygonal column shape, or a truncated cone shape.

The light guide member 40 is made of the same material such as glass having a uniform refractive index. Note that the light guide member 40 is not limited to the same material such as glass having a uniform refractive index, and may be configured of, for example, two materials of a core and a clad having different refractive indexes. Further, the light guide member 40 may be made of a material that has little absorption with respect to the fluorescence wavelength to be measured, for example, an absorption coefficient of 0.1 or less. The light guide member 40 has a light guide path 41 formed along one axis AX.

On one axial axis AX, a fluorescence optical system 50 that is an optical system for fluorescence emitted from the light guide member 40 is provided. The fluorescence optical system 50 condenses the fluorescence emitted from the light guide member 40 toward one axis AX.

The fluorescent optical system 50 includes a collimating lens 51 that converts the fluorescent light into parallel light, and a condensing lens 52 that condenses the fluorescent light converted into parallel light by the collimating lens 51 on one axis AX.

Between the condenser lens 52 and the collimating lens 51, there is provided a fluorescent bandpass filter FF that transmits a band including the wavelength of fluorescence. The wavelength of fluorescence emitted by excitation of NADH as a coenzyme is 450 to 510 nm, more specifically, around 491 nm. Therefore, in this embodiment, the wavelength range transmitted by the fluorescent bandpass filter FF is 440 to 510 nm.

On one axis AX, a detection unit 60 that detects fluorescence that has passed through the fluorescence optical system 50 is provided. The detection unit 60 includes a photomultiplier tube, a photodiode detector, and a spectrophotometer including these, and detects the concentration of the substrate in the gas sample based on the detected fluorescence light quantity or spectral characteristics.

Case C is formed in a cylindrical shape covering the periphery of the light source LT, the excitation light optical system, the flow cell 30, the light guide member 40, the fluorescence optical system, and the detection unit 60. That is, the case C accommodates each of the light source LT, the excitation light optical system 20, the flow cell 30, the light guide member 40, the fluorescence optical system 50, and the detection unit 60 therein. Accordingly, the case C is configured so that outside light does not enter the case C.

The case C has two through holes HA provided through the case C in a direction perpendicular to the one axis AX. By inserting the gas flow path 31 into the two through holes HA, the gas flow path 31 can be mounted on one axis AX. That is, the two through holes HA function as a first mounting portion that can mount the gas flow path 31 on one axis AX.

The case C is formed with two through holes HB provided through the case C in a direction perpendicular to the one axis AX. By inserting the solution flow path 32 having a tube structure into the two through holes HB, the solution flow path 32 can be mounted on one axis AX. That is, the two through holes HB function as a second mounting portion that can mount the solution flow path 32 on one axis AX.

The case C is formed with a protruding portion P formed so as to protrude so that inner walls facing each other approach each other in a direction perpendicular to the one axis AX. The protrusion P is formed along the circumferential direction of the inner wall of the case C. Further, the protruding portion P is formed between the through hole HA and the through hole HB on one axis AX. The enzyme holding film 33 is mounted on one axis AX by fitting the enzyme holding film 33 into the protruding portion P. In other words, the protruding portion P functions as a third mounting portion that can mount the enzyme holding film 33 on one axis AX.

Thus, the gas flow path 31, the liquid flow path 32, and the enzyme holding film 33 can be detached from the case C, respectively. Note that at least one of the gas channel 31, the liquid channel 32, and the enzyme holding film 33 may be detachable, and the rest may be fixed to the case C.

In addition, when the solution flow path 32 is a structure like an airtight container, the through-hole HB does not need to be provided. In this case, it is preferable to provide a groove G that is recessed outward from the inner wall of the case C. Further, the groove G may be formed along the circumferential direction of the inner wall of the case C. By fitting the closed container-like solution flow path 32 in the groove G, the solution flow path 32 can be mounted on one axis AX. In this case, the groove G functions as a second attachment portion that can attach the solution flow path 32 on one axis AX.

FIG. 2 shows an enlarged cross section of the flow cell 30 along one axis AX. As shown in FIG. 2, on the light source LT side of the flow cell 30, there is provided a gas flow path 31 that has a window W that transmits excitation light and through which a gas sample containing a substrate flows. A through hole H <b> 1 that penetrates the gas flow path 31 and the outside is provided on the detection section 60 side of the gas flow path 31.

A solution channel 32 through which a solution containing a coenzyme flows is provided on the detection unit 60 side of the flow cell 30. The solution flow path 32 includes an upstream connection portion provided on the upstream side in the solution flow direction, a downstream connection portion provided on the downstream side in the solution flow direction, an upstream connection portion, and a downstream connection. And a curved portion that is curved toward the light source LT side. On the gas channel 31 side of the curved portion of the solution channel 32, a through hole H2 that penetrates the solution channel 32 and the outside is provided.

The solution flowing through the solution flow path 32 contains a coenzyme and a buffer solution having a pH value considering the optimum pH value of the enzyme or coenzyme as components.

The enzyme holding film 33 for holding the enzyme is provided in contact with both the gas channel 31 and the solution channel 32 so as to block the through hole H1 of the gas channel 31 and the through hole H2 of the solution channel 32. ing. That is, the enzyme holding film 33 is a diaphragm that allows the held enzyme to contact the solution in the solution channel 32 and the gas sample in the gas channel 31 and separates the solution channel 32 and the gas channel 31. .

The enzyme holding film 33 is obtained by immobilizing an enzyme on a carrier that is a film material. Examples of the carrier for the enzyme holding film 33 include polytetrafluoroethylene, polydimethylsiloxane, polypropylene, polyethylene, polymethyl methacrylate, polystyrene, polyvinylidene fluoride, nitrocellulose, and cellulose.

The flow cell 30 is formed to be recessed along one axis AX so as to go from the detection unit 60 side to the light source LT side, and has a through hole H3 penetrating the solution flow path 32 and the outside. The through hole H <b> 3 includes a small diameter portion having a size equivalent to the outer diameter of the light guide member 40, and a large diameter portion formed by expanding from the small diameter portion toward the fluorescence optical system 50.

Therefore, the light guide member 40 is held by the flow cell 30 by fitting the light guide member 40 to the small diameter portion. In other words, the flow cell 30 functions as a holding member that holds the light guide member 40.

The flow cell 30 has a space SP between a side surface SS of the light guide member 40 extending along one axis AX and a wall portion of the enlarged diameter portion of the through hole H3. When the refractive index of the light guide member 40 is n ₁ and the refractive index of the space SP is n ₂ , the numerical aperture (NA) is given by the following equation.

Here, in order to maximize the numerical aperture (NA) under the condition that the refractive index n ₁ of the light guide member 40 is fixed, n ₂ needs to be 1, that is, the space SP needs to be air. Therefore, the numerical aperture (NA) of the light guide member 40 is maximized by forming an air layer around the side surface SS.

Here, the light guide path 41 of the light guide member 40 may be formed so as to reduce the amount of excitation light guided. Specifically, the incident angle with respect to the light guide member 40 of at least a part of the excitation light that has passed through the solution flow path 32 of the flow cell 30 is greater than the maximum light reception angle that can be totally reflected by the inner surface of the light guide path 41 of the light guide member 40. It is better to make it larger.

FIG. 3 shows an aspect of the excitation light emitted from the light source LT. In FIG. 3, the alternate long and short dash line arrow indicates the excitation light LT1. The excitation light LT1 emitted from the light source LT is converted into parallel light by the collimator lens 21.

The excitation light LT1 that has been converted into parallel light by the collimator lens 21 is subjected to removal of light having a wavelength other than a predetermined band in the excitation light bandpass filter EF. The excitation light LT1 that has passed through the excitation light bandpass filter EF is collected by the ball lens 22 toward the solution flow path 32 of the flow cell 30.

The ball lens 22 has a short focal length even among the biconvex lenses. Therefore, by using the ball lens 22 in the excitation light optical system 20, it is possible to increase the amount of excitation light LT1 incident at an incident angle larger than the maximum light receiving angle of the light guide path 41. Here, the ball lens 22 has a low aberration but has a short focal length, which is advantageous for downsizing the biosensor 10. For this reason, by increasing the diameter of the light guide member 40, defocus due to the deterioration of the aberration of the ball lens 22 is allowed. That is, the diameter of the light guide member 40 is ideally the minimum diameter that allows the size of the light source LT and lens aberration. Further, when the excitation light LT1 is an annular light and the diameter of the annular light incident on the ball lens 22 is increased, the aberration of the ball lens 22 can be reduced and the focal length can be further shortened. For this reason, it becomes easy to increase the amount of the excitation light LT1 incident beyond the maximum light receiving angle of the light guide path 41.

Further, the excitation light optical system 20 including the ball lens 22 is configured with a numerical aperture larger than the numerical aperture of the light guide member 40. For this reason, the excitation light LT1 incident on the light guide path 41 at an acute angle with respect to the one axis AX increases. That is, the amount of excitation light LT1 incident on the light guide 41 at an incident angle larger than the maximum light receiving angle of the light guide 41 is increased. As a result, the amount of the excitation light LT1 that is transmitted outside without being guided through the light guide member 40 increases.

Further, as described above, as long as the excitation light LT1 exhibits an annular distribution even when the optical system is not configured with an optical system larger than the numerical aperture of the light guide member 40, as described below, Collimation of the excitation light LT1 (light guide to the detection unit 60) can be suppressed by the arrangement of the subsequent collimating lens.

Here, the excitation light LT1 that has passed through the flow cell 30 enters the light guide member 40 at various incident angles. At that time, the excitation light LT1 that is incident at an incident angle that is less than the maximum light reception angle that can be totally reflected by the inner surface of the light guide 41 has a certain distribution due to the influence of the light source LT and the excitation light optical system 20. The distribution of the excitation light LT1 is also maintained in the light guide path 41. As a result, the density of the excitation light LT1 is generated in the light guide path 41.

The collimating lens 51 is arranged so that the lightest light of the excitation light LT1 is collimated by the collimating lens 51. That is, the collimating lens 51 is arranged so that the excitation light LT1 is defocused at the focal position of the collimating lens 51 in the light guide path 41. By arranging the collimating lens 51 in this way, a lot of excitation light L1 can be diffused without being collimated by the collimating lens 51.

The excitation light LT1 converted into parallel light by the collimating lens 51 is reflected by the fluorescent bandpass filter FF.

FIG. 4 shows a mode of fluorescence emitted from the flow cell 30. In FIG. 4, the alternate long and short dash line indicates the fluorescence LT2. When the coenzyme receives the excitation light LT1, it emits fluorescence LT2. The fluorescence LT2 passes through the solution in the solution flow path 32 and enters the light guide path 41 of the light guide member 40. The fluorescent light LT 2 guided through the light guide path 41 is emitted from the emission end of the light guide member 40 toward the collimator lens 51.

Fluorescence LT2 collimated by the collimating lens 51 removes light having a wavelength other than a predetermined band by the fluorescence bandpass filter FF. The fluorescence LT2 that has passed through the fluorescence bandpass filter FF is condensed toward the detection unit 60 by the condenser lens.

As described above, according to the biosensor 10 which is the detection device of the present invention, the excitation light LT1 emitted from the light source LT is irradiated to the flow cell 30 without passing through the optical fiber used in the conventional detection device. The Accordingly, it is not necessary to configure the excitation light optical system 20 according to the numerical aperture of the optical fiber, and thus the excitation light optical system 20 can be configured with a numerical aperture higher than the numerical aperture of the optical fiber.

As a result, the biosensor 10 has high utilization efficiency of the excitation light LT1, and can increase the detection accuracy of the specific substance by increasing the amount of fluorescence emitted from the coenzyme. Further, since the biosensor 10 does not have an optical fiber, the number of parts can be reduced, and the apparatus can be downsized.

The biosensor 10 also has a light guide member 40 provided in contact with the flow cell 30. Thereby, a part of the excitation light LT1 that has entered the light guide 41 beyond the maximum light receiving angle of the light guide 41 passes through the light guide 41 without being guided. Therefore, the amount of excitation light LT1 detected by the detection unit 60 can be reduced, and detection accuracy can be improved.

The biosensor 10 according to Example 2 will be described. The biosensor 10 according to the second embodiment is different from the biosensor 10 according to the first embodiment in that the biosensor 10 includes a light shielding member for shaping the radiation distribution of the excitation light LT1 emitted from the light source LT into an annular shape. In addition, about the structure same as Example 1, description is abbreviate | omitted by attaching | subjecting the same code | symbol to the same location, and it is the same also about subsequent Examples.

FIG. 5 shows a cross section along one axis AX of the biosensor 10 according to the second embodiment. As shown in FIG. 5, the excitation light optical system 20 includes a light shielding member 70 that is arranged on one axis AX and that can shield the excitation light LT1.

The light shielding member 70 is formed in a disk shape, for example. The size of the light shielding member 70 may be formed larger than the diameter of the light guide path 41 of the light guide member 40. By disposing the light shielding member 70 formed in this way on one axis AX, it is possible to block the excitation light LT1 that travels straight on the one axis AX.

FIG. 6 shows an aspect of the excitation light LT1 emitted from the light source LT in the biosensor 10 of the second embodiment. In FIG. 6, the one-dot chain line arrow indicates the excitation light LT1. As shown in FIG. 6, a lot of excitation light LT1 is incident on the light guide path 41 at an angle larger than the total reflection angle. Thereby, most of the excitation light LT1 passes through the light guide member 40 without being guided through the light guide path 41.

Specifically, the excitation light LT1 that has not been absorbed by the coenzyme (NADH) in the solution flow path 32 enters the light guide member 40. A part of the excitation light LT1 is incident at a wide angle with respect to the axis AX, that is, at an incident angle larger than the maximum light receiving angle that can be totally reflected by the inner surface of the light guide path 41 of the light guide member 40. The excitation light LT1 incident at an incident angle larger than the maximum light receiving angle is transmitted through the light guide 41 from the side surface SS to the outside of the light guide member 40.

As described above, according to the biosensor 10 according to the present embodiment, the excitation light LT1 that travels straight on one axis AX can be blocked. Further, the incident angle of the excitation light LT1 incident on the light guide member 40 can be increased, and a large amount of the excitation light LT1 can be prevented from being guided in the light guide path 41. As a result, the amount of excitation light LT1 detected by the detection unit 60 can be reduced, and the detection accuracy can be improved.
[Modification]
When the excitation light optical system 20 includes the light shielding member 70 as in the present embodiment, the amount of excitation light LT1 that guides the light guide path 41 can be reduced. Therefore, the biosensor 10 may be configured without providing the fluorescence optical system 50.

FIG. 7 shows a configuration of a modification of the biosensor 10 according to the present embodiment. As shown in FIG. 7, the biosensor 10 does not have the fluorescence optical system 50 and the fluorescence filter FF. Thus, by configuring the biosensor 10, it is possible to reduce the size of the biosensor 10.

The biosensor 10 according to Example 3 will be described. The biosensor 10 according to the third embodiment is different from the biosensor 10 according to the first and second embodiments in that the shape of the flow cell 30 is different.

FIG. 8 shows an enlarged cross section of the flow cell 30 along one axis AX of the biosensor 10 according to the third embodiment. As shown in FIG. 8, the light guide member 40 is formed such that a portion 34 in contact with the solution flow path 32 of the flow cell 30 is narrowed toward the fluorescence optical system 50. That is, the portion 34 of the light guide member 40 that contacts the solution flow path 32 of the flow cell 30 is inclined so as to have an angle with respect to one axis AX. Therefore, the excitation light LT1 applied to the portion 34 of the light guide member 40 that contacts the solution flow path 32 of the flow cell 30 is reflected toward the solution flow path 32 of the flow cell 30.

As described above, according to the biosensor 10 according to the present embodiment, a part of the excitation light LT1 incident on the light guide member 40 can be reflected toward the solution flow path 32 of the flow cell 30, so that the fluorescence The light emission efficiency of LT2 can be improved.

In order to positively reflect the excitation light LT1 toward the solution flow path 32, a portion 34 that contacts the solution flow path 32 of the flow cell 30 may be provided with a reflection member that reflects the excitation light LT1. Further, in order to diffusely reflect the excitation light LT1, the portion of the flow cell 30 that contacts the solution flow path 32 may have an uneven surface.

The biosensor 10 according to Example 4 will be described. The biosensor 10 according to the fourth embodiment is different from the biosensor 10 according to the first embodiment in that it does not include the excitation light optical system 20.

FIG. 9 shows a cross section along one axis AX of the biosensor 10 according to the fourth embodiment.

As shown in FIG. 9, on one axis AX, a long pass filter LF for cutting a band including the wavelength of the excitation light LT1 is provided between the collimating lens 51 and the fluorescent band pass filter FF.

FIG. 10 shows an aspect of the excitation light LT1 emitted from the light source LT of the biosensor 10 according to the fourth embodiment. In FIG. 10, the alternate long and short dash line arrow indicates the excitation light LT1. As shown in FIG. 10, the excitation light LT <b> 1 emitted from the light source LT passes through the flow cell 30 and is incident on the light guide member 40.

Here, the excitation light LT1 exceeding the maximum light receiving angle of the light guide 41 passes through the light guide 41 without being guided. The excitation light LT1 guided through the light guide path 41 is collimated by the collimating lens 51 and attenuated by the long pass filter LF.

FIG. 11 shows an aspect of the fluorescence LT2 emitted from the flow cell 30 of the biosensor 10 according to the fourth embodiment. In FIG. 11, the alternate long and short dash line arrow indicates the fluorescence LT2.

The fluorescence LT2 emitted in the solution flow path 32 of the flow cell 30 is guided in the light guide path 41 of the light guide member 40. The fluorescence LT2 emitted from the light guide member 40 is collimated by the collimating lens 51, and passes through the long pass filter LF and the fluorescence band pass filter FF. The fluorescence LT2 that has passed through the fluorescence bandpass filter FF is condensed toward the detection unit 60 through the condenser lens 52.

As described above, according to the biosensor 10 according to the present embodiment, since the excitation light optical system 20 is not provided, it is possible to directly irradiate the solution flow path 32 with high intensity excitation light. . For this reason, the light emission amount of the fluorescence LT2 can be increased, and the size of the device can be reduced by reducing the number of parts of the device.

A biosensor 10 according to Example 5 will be described. The biosensor 10 according to the fifth embodiment is different from the biosensor 10 according to the first to fourth embodiments in that the shape of the gas flow path 31 of the flow cell 30 is different.

FIG. 12 shows a cross section along one axis AX of the biosensor 10 according to the fifth embodiment. In FIG. 12, the excitation light optical system 20 has a collimating lens 21, but does not have a ball lens 22.

The gas flow path 31 of the flow cell 30 has a lens portion 31 a formed so as to have a curved surface that is convex toward the enzyme holding film 33 around the one axis AX.

The lens unit 31 a condenses the excitation light LT <b> 1 converted into parallel light by the collimating lens 21 toward the enzyme holding film 33. Therefore, according to the biosensor 10 according to the present embodiment, the ball lens 22 of the excitation light optical system 20 is not necessary. As a result, the number of parts of the apparatus is reduced, and the apparatus can be miniaturized.

A biosensor 10 according to Example 6 will be described. The biosensor 10 according to the sixth embodiment is different from the biosensor 10 according to the first to fifth embodiments in that the arrangement positions of the light source LT and the detection unit 60 are different.

That is, in Examples 1 to 4, the light source LT, the excitation light optical system 20, the flow cell 30, the light guide member 40, the fluorescence optical system 50, and the detection unit 60 are arranged on one axis AX, but the light source LT In addition, at least one of the detection units 60 may not be arranged on one axis AX.

FIG. 13 shows a cross section along one axis AX of the biosensor 10 according to the sixth embodiment. As illustrated in FIG. 13, the light source LT and the detection unit 60 are respectively disposed on an axis AX2 and an axis AX3 that are orthogonal to one axis AX. Further, the mirror MR1 and the mirror MR2 are disposed at a position where the axis AX2 and the axis AX3 intersect with one axis AX. That is, the excitation light LT1 emitted from the light source LT is reflected by the mirror MR1 so as to reach the excitation light optical system 20. The fluorescence LT2 that has passed through the fluorescence optical system 50 is reflected by the mirror MR2 so as to reach the detection unit 60.

In Examples 1 to 5, the excitation light optical system 20 and the fluorescence optical system 50 are arranged on one axis AX that is the same axis as the optical axis of the excitation light LT1. However, as described in the present embodiment, the excitation light optical system 20 and the fluorescence optical system 50 do not have to be arranged on one axis AX that is the same as the optical axis of the excitation light LT1, and the excitation light The optical axis of LT1 and the optical axis of fluorescence LT2 may deviate from the axis AX as long as the fluorescence LT2 can reach the detection unit 60.

The configurations of the devices and apparatuses in the above-described embodiments are merely examples, and can be appropriately selected or changed according to the application.

DESCRIPTION OF SYMBOLS 10 Biosensor 20 Excitation light optical system 30 Flow cell 31 Gas flow path 32 Solution flow path 33 Enzyme holding film 40 Light guide member 41 Light guide path 50 Fluorescence optical system 60 Detection part 70 Light shielding member AX One axis

Claims

A gas flow path through which a gas sample flows, a solution holding unit that holds a solution containing a coenzyme that emits fluorescence when excited by excitation light before or after a catalytic reaction with the gas sample, and a catalyst for the catalytic reaction A reaction part including an enzyme-holding membrane on which an enzyme is held and arranged on one axis;
A light guide member provided on the one axis in contact with the reaction portion and forming a light guide along the one axis;
And a detection unit that detects the fluorescence that has passed through the light guide path.
The detection apparatus according to claim 1, further comprising a fluorescence optical system that includes a first collimating lens that converts the fluorescence that has passed through the light guide path into parallel light, and that collects the fluorescence.
The detection apparatus according to claim 2, wherein the fluorescence optical system includes a condensing lens that condenses the fluorescence that has passed through the first collimating lens.
The detection apparatus according to claim 2 or 3, wherein the fluorescence optical system is configured such that the excitation light that has passed through the light guide path is defocused.
5. The excitation light optical system according to claim 2, further comprising an excitation light optical system that is provided on the opposite side of the fluorescence optical system when viewed from the reaction part and collects the excitation light on the reaction part. Detection device.
The excitation light optical system is arranged on the one axis to collimate the excitation light, and the excitation light collimated by the second collimator lens is condensed on the reaction unit. The detection apparatus according to claim 5, further comprising a condensing lens.
The detection device according to claim 5 or 6, wherein the numerical aperture of the excitation light optical system is larger than the numerical aperture of the light guide member.
An incident angle of at least a part of the excitation light that has passed through the reaction portion with respect to the light guide member is configured to be larger than a maximum light reception angle that can be totally reflected by the inner surface of the light guide path of the light guide member. The detection apparatus according to claim 1, wherein
The detection device according to any one of claims 1 to 8, further comprising a space along a side surface extending in a direction along the one axis of the light guide member.
A holding member for holding the light guide member so as to cover the periphery of the light guide member;
The detection device according to claim 9, wherein a space is provided between the holding member and the side surface of the light guide member.
The detection apparatus according to claim 5, wherein the excitation light optical system includes a light shielding member that is disposed on the one axis and is capable of shielding the excitation light.
The detection device according to any one of claims 2 to 11, wherein the light guide member is formed such that a portion in contact with the reaction portion is narrowed toward a fluorescence optical system.
13. The detection apparatus according to claim 1, wherein an optical filter that transmits a band including the fluorescence wavelength is provided between the light guide member and the detection unit.
14. The detection device according to claim 1, wherein at least one of the gas flow channel, the solution holding unit, and the enzyme holding film is detachable from the detection device.